(1) sometime意為“某個時候”，可用于將來或過去時。如：
Come to see us sometime. 什么時候來看看我們。
I'll speak to him about it sometime. 我什么時候將和他談談這事。
I saw him sometime in May. 我是五月什么時候見到他的。
I bought it sometime last spring. 我是去年春天什么時候買的。
Our house was built sometime around 195o. 我們的房子是195o年前后什么時候蓋的。
【注】這樣用的 sometime 也可寫成 some time (即分開寫)。如：
He died some time last year. 他是去年什么時候死的。
(2) some time 有兩個用法：用作副詞詞組，意為“任何時候”或“某個時候”(= sometime)；用作名詞詞組，意為“一段時間”(不能寫成 sometime)。如：
It takes quite some time. 它要花相當多時間。
Please phone me some time next week. 下個星期什么時候給我打個電話吧。
We lived in the country for some time. 我們在農村住過一段時間。
(3) sometimes 意為“有時”。如：
He sometimes writes to me. 他有時給我寫信。
Sometimes he went there by bus. 有時他坐公共汽車去那兒。